Radio system



p 9, 1930- 1 s. VON ARco 1,775,181:

RADIO SYSTEI F1165. NOV- 27. 1925 I NVENTOR emu van Anca ORNEY Patented Sept. 9, 1930 UNITED STATES PATENT, OF ICE (mono von ARGO, or BERLIN, GERMANY, Assrcnon 'ro .epsnnnscrrarrrnn nanni- LOSE TELEGRAPHIE M. B. 11., or BERLIN, oaamanv, n oonroan rron or eminen RADIO SYSTEM Application filed November 27, 1925, Serial No. 71 614, and in Germany December 24, 1924.

The purpose of this invention is to construct a radio system which will make possible the coupling of a multiplicity of tubes for radio frequency amplification.

5 It is an object of this invention to couple a multiplicity of triodes in such a manner that their inherent impedance is duly compensated for so that oscillations in the several triodes and their associated circuits may be controlled and regulated.

This invention accomplishes the above result by inserting a resistance or any other impedance, in addition to the regular coupling impedance, in the output or anode 5' circuits of the various triodes used in this system.

It is well known in the art that in the usual coupling of a plurality of tubes for receiving radio signals the inherent impedance of the tubes gives rise to radio oscillations which seriously affect the operation of this system.

In order to avoid reaction between oscillatlon circuits, and still insure a satisfactory transmission or transfer of energy from one circuit to another, it is common to use electron tubes for the coupling of the circuits. In this construction one of the oscillation circuits is inserted in the grid-cathode circuit, while the other oscillation circuit is connected in the anode-cathode circuit and in this manner the amplifying action of the tube is utilized, which results in an arrangement for the transfer and amplification of alternating current of a kind known especially in high frequency practice, where it is extensively used. However, it has been found that the tubes used for thispurpose in practice involve considerable coupling by way of and in virtue of the internal tube capacity, with the result that in such devices as here dealt with, upon changingthe tuning of one of the circuits, there manifests itself a by no means inconsiderable effect upon the tuning of'the other circuit. The coupling through the tube capacity is in many cases sufiioiently close to "cause the system consisting of the electron tubes and oscillation circuits to start oscillating spontaneously.

I In order that the disadvantages of unduly close coupling through the tube capacity'may be prevented according to the present invention, a high impedance is inserted into one of the leads uniting the oscillation circuit with the electrodes of the tube, as shown by way of example in the accompanying drawing. Referring to the drawing, it will be seen that four oscillation circuits S S S 8*, each of which is sharply tuned, are interconnected through tubes E E and E in well-known manner. According to the in-- vention. a high ohmic resistance R R R respectively, is inserted in the anode lead of each of the tubes, the said resistances having to be of such value that their effective resistance for the frequency to be transferred will: be approximately of an order of magnitude of the impedance of the anode grid capacity of each individual tube, it being evident that this results in looser coupling between the different oscillation circuits. This is associated with the disadvantage of lower amplification, for on account of the high load resistance in the anode circuit the working characteristic of the indivdual tubes is flattened. This diminution or loss of amplification, however, can be compensated by using a plurality of such combinations comprising a hot-cathode tube and oscillation circuits.

'The use of a great number of tubes when connected in away as hereinbefore set forth is practicable because the re-action of the individual oscillation circuits is avoided, so that disturbing self-excitation will not arise.- Of course, it is feasible to employ inductive chokers in lieu of ohmic resistance, and also to insert condensers in the anode circuits, by a corresponding modification of the connections including supplying the direct current separately to the individual tubes.

Having thus described my invention, I

claim 1. In a wireless system a plurality of associated triodes arranged for cascade amplification, a sharply resonant circuit for each triode, said resonant circuits being coupled by said triodes only, and a circuit connecting the anode of each triode with its respective resonant circuit including an impedance element of the order of magnitude of the natural capacitive impedance of its respective tri- 1 tive'the natural coupling between the input r 3 and output circuits.

GEORG- voN A360. 

